1. Field of the Invention
The present invention relates to a scroll type compressor, and more particularly relates to a scroll type compressor effectively used as a refrigerant compressor in an air conditioner for automobile use.
2. Description of the Related Art
Conventionally, there are provided variable discharge compressors of the scroll type which are disclosed in Japanese Unexamined Patent Publication Nos. 61-291792, 62-91680 and 5-332263. The operation of these variable discharge compressors is as follows:
Bypass holes communicated with the suction chamber through the intermediate pressure chamber are formed on the end plate of the fixed scroll member. An opening and closing valve mechanism is provided in the communicating section between the intermediate pressure chamber and the suction chamber. This opening and closing valve mechanism is controlled by an electric means such as a solenoid valve or motor, so that the bypass hole is opened and closed, and the variable discharge operation can be accomplished.
According to the variable discharge compressor of scroll type disclosed in Japanese Unexamined Patent Publication 3-237285, a piston in the opening and closing valve mechanism causes gas, in the middle of the compression cycle, to flow to the suction chamber side through a bypass hole. This piston is moved when the discharge pressure of refrigerant flowing in the downstream of the discharge valve is applied.